European Patent Application EP 22 495 describes 2-(substituted phenyl)imidazo[4,5-b]pyridines as cardiotonics and hypertensive agents. European Patent Application EP 72 926 describes 2-(substituted phenyl)imidazo[4,5-b]- and [4,5-c]pyridines having positive inotropic properties. European Patent Application EP 79 083 describes 2-phenylimidazo-[4,5-]pyridines having vasodilating, positive inotropic and platelet aggregation-inhibiting properties and which do not have an inhibitory action on the myocardial phosphodiesterase. German Patent Application DE 32 24 512 describes, inter alia, 2-phenylimidazo-[4,5-b]pyridines for the treatment of cardiac insufficiency by increasing the contractility of the heart, and for lowering the blood pressure. German Patent Application DE 32 25 386 describes 2-naphthylimidazo-[4,5-b]pyridines having positive inotropic, hypotensive and platelet aggregation-inhibiting properties. German Patent Application DE 23 61 757 describes 2-(substituted phenyl)imidazo[4,5-b]pyridines having hypotensive, positive inotropic, platelet aggregation-inhibiting and bleeding time-prolonging properties.